I'm not sure what I think of this as of yet, but hopefully all the fancy functionality now unavailable to disc-based games still works with games bought and downloaded from Xbox Live. At least those are still available to you on any Xbox One, once you've logged in.

Did they remove their Family Sharing plan with this announced change? If so, they just pulled what could have been a revolutionary feature.

The second link in my post discusses the features lost due to this change, and the family sharing is one of them. At least for disk based games. The person Engadget spoke to ensures that the online games library still works with games bought on Xbox Live, so there's hope that the family sharing still works with games that are not disk based. Hopefully Microsoft have learnt their lesson and will be more forthcoming with information this time around...